A Quantum Diaries Survivor

The CDF collaboration has recently released a study of the production of pairs of W bosons in a large bounty of proton-antiproton collisions produced by the Tevatron collider -3.6 inverse femtobarns of them, or roughly 300 trillions, give or take 6%.The measurement of the production cross section of this clean and rare electroweak process (its absolute rate, that is) is the most precise ever obtained so far, and reaches down to a level of uncertainty which cannot be improved further significantly at the Tevatron, because it is now limited by the uncertainty in the overall integrated luminosity mentioned above.

I received an interesting question today from an Alex Ziller in the comments thread of a recent post. Here it is:Do you think blogging actually improves Science? (I know, one should first define what "improving Science" actually means).I think this matter has been debated elsewhere not too long ago -where by "elsewhere" I mean "some site I sometimes visit, can't recall where". Nevertheless, I consider it a crucial question to ask, and one with several facets. Here is my short answer to Alex -of the kind of depth a comments thread is worth:

A few days ago I produced a summary of a poster I presented at Physics in Collisions this week, which dealt with the searches for the Standard Model Higgs boson that CMS will undertake, and the results it can obtain in a scenario when a certain amount of data is collected at the full design energy of the LHC.Here, instead, I wish to summarize the other poster I presented at the same venue, which concerned the combination of the most sensitive search channels, the sensitivity of CMS with a given amount of data, and the derating of its significance reach or observation power entailed by the running of LHC at a smaller-than-design beam energy. But I will do this only as a way of introducing a more interesting discussion, as you will see below.

This morning I attended the first session of the Physics in Collisions conference in Kobe, which dealt with Electroweak Physics. The four talks I could listen to were all of very good quality, and I am not ashamed to say that I did learn a thing or two, despite this is a field of investigations on which I have focused for over a decade. Also, I decided that conferences featuring few, long talks are definitely better than ones which try to cram dozens of small contributions in tight schedules: at least, the session conveners are not required to play the watchdog and struggle to keep people within their allotted time, and post-talk questions and comments are actually encouraged rather than suppressed.

Today I wish to offer you the preview of a poster which I am going to show on September 1st in Kobe, Japan, at a session of the 29th edition of the Physics in Collisions conference.

Today I wish to offer you the figure attached at the bottom of this article, which shows a combination of recent determinations of the rate at which the Tevatron proton-antiproton collisions produce single top quarks.

Today, although fully submerged by an anomalous wave of errands which had been patiently waiting for my return at work, I heroically managed to dig out of the ArXiv a paper worth a close look.

The figure shown below represents the best measurement of the top quark mass ever obtained by a single experiment, and it is a determination with a less than 1% total uncertainty. It has been approved last week by the CDF experiment at Fermilab.The CDF experiments collects proton-antiproton collisions delivered by the Tevatron collider, which imparts the projectiles with 1 TeV of energy each, for a center-of-mass energy of 2 TeV. This is still the highest energy ever achieved by a collider, although the record is going to be soon stripped off Fermilab by the Large Hadron Collider, which is due to start colliding protons with other protons at 7 TeV of energy this coming fall.

The World Conference on Science Journalism held in London 2009 has its own web site, of course. Today they were so kind to let me know they had published there the recordings of all sessions, among which was the one where I gave my speech. The session title was "Blogs, Big Physics, and Breaking News", it featured Matin Durrani as chair, and Matthew Chalmers, myself, and James Gillies as speakers. The abstract ran as follows:How are blogs changing the way science news develops and is reported?The commissioning of the Large Hadron Collider at CERN will offer atelling case study over the next few years. Who will be first with news

A couple of months ago I wrote here about the first observation of a process called "diboson production", a quite rare occurrence in hadronic collisions: for the first time, the CDF collaboration could observe that rare process in events containing hadronic jets, which are usually riddled by enormous backgrounds.

Tonight you have a chance to contribute to science -namely, the knowledge of our solar system- and have a lot of fun at the same time. Do you want to know how ? Then please read on.Comet Swift-Tuttle (left, courtesy NASA) may be far away by now, but the debris that gets thrown out in space during each of its passages in the proximity of our Sun traces the full elliptical orbit of the comet, like droplets of sweat of an athlete running the 10,000 meters in a stadium. And tonight, the Earth is going to plunge in the core of the filament of debris following the comet's orbit.

Amateur astronomers fond of visual observation of faint galaxies and other fuzzy treasures of the night sky are always in search of the best observative site, where to drag their large Dobsonian telescopes.Unfortunately, their road is always uphill - also in a metaphorical sense: light pollution is growing everywhere at a disturbing rate, and it has already erased all but the brightest stars from our urban and suburban skies.Many of our kids grow without having seen the Milky Way, and the few who are drawn to astronomy are surprised to realize, from the tales of older dogs like me, that it did not use to be that way.